1. Field of the Invention
The present invention pertains to diesel engines of the type having precombustion chambers, and more specifically, to improvements in those precombustion chambers which will permit greater efficiency.
2. Description of the Prior Art
Diesel engines designed according to the precombustion chamber system have the combustion chamber divided into a precombustion chamber, which is incorporated into the cylinder head, and a main combustion chamber which is positioned between the bottom edge of the cylinder head and the heads of the piston or crown. The precombustion chamber into which the fuel is injected and in which only a partial combustion takes place, is connected to the main combustion chamber by means of a narrow slot or flow passage.
In operation, as the piston moves in the direction of the cylinder head air is forced into the precombustion chamber and at the end of this compression stroke, fuel is injected into the precombustion chamber. Subsequently, a flame front is propagated down a flow channel from the precombustion chamber into a secondary combustion chamber formed in the piston head. The combustion of this fuel-air combination generates the thrust necessary to produce the power stroke of the piston.
It should be noted that the precombustion chamber, as well as the flow passages of the prior art, have significantly different geometries than the present invention. In U.S. Pat. No. 4,122,804 to Kingsbury et al, precombustion chamber 50 is almost spherical in shape instead of having the elongated cylindrical geometry of the presently claimed combustion chamber. Furthermore, it should be noted that flow passage 72 has acute angles in it as well as sharp-edged orifices where the flow passage interconnects with the precombustion chamber. This basic simplistic design of the precombustion chamber and flow passage yields inherent efficiency problems as well as inherent problems of incomplete combustion.